- Utah’s HB 340 was signed on March 25, 2025 and took effect on May 7, 2025, the first law of its kind in the US.
- Limit: 1,200 W AC, plugged into a standard 120 V outlet.
- No permit, no utility approval, no notification and no fees.
- Exported power is not credited, so the savings come from what you use yourself.
When Utah’s legislature passed HB 340 unanimously in early 2025, plug-in solar in the US went from a legal grey area to a real option, at least in one state. The law became the template that Virginia, Maine, New Jersey and others later adapted. Here is what it says and how to use it.
In this article
What HB 340 allows
A “portable solar generation device” can be plugged into a standard 120-volt outlet without an interconnection agreement, as long as it meets four conditions:
- Maximum 1,200 W AC output, measured at the inverter.
- Certified by UL or another nationally recognized testing laboratory.
- Compliant with the National Electrical Code (NEC 2023).
- Anti-islanding: it shuts off automatically when grid power is lost.
There is no permit, no application, no fee and no requirement to notify Rocky Mountain Power or any other utility.
What you give up
The law treats plug-in solar as “offset only”. The device reduces what your meter records while you use the power, but any surplus flowing out to the grid is not compensated. That is the trade for skipping the interconnection process. A larger system therefore is not always better; see how self-consumption works.
The law also gives utilities liability protection for damage caused by compliant devices. In plain terms: if your kit causes a problem, the utility is not on the hook. That is another reason to buy certified equipment and follow the instructions.
What about renters and HOAs?
HB 340 does not address landlords or homeowners associations. Your lease or HOA covenants still apply. Many landlords are fine with a clamp-on kit that leaves no marks, but get agreement in writing. Our guide to landlords and HOAs has tips.
How much sun Utah gets
Utah is one of the best places in the country for small solar. A south-facing panel tilted around 30 degrees can produce roughly 1,600 kWh per kW of panels per year along the Wasatch Front. That means:
| Setup | Estimated yearly output |
|---|---|
| 800 W, tilted, south, no shade | ~1,250 kWh |
| 800 W, vertical on a south railing | ~900 kWh |
| 800 W, vertical, east or west | ~700 kWh |
| 1,200 W, tilted, south | ~1,900 kWh |
Utah’s electricity is relatively cheap, around 12-14 cents per kWh for residential customers. An 800 W kit using 75% of its output at home would save roughly $90-130 a year, a payback of six to nine years on a typical kit. Cheap power stretches payback compared with California or New England, but the sun makes up for part of it. Check your numbers with the calculator.
Which kits can you buy in Utah?
Because Utah legalized plug-in solar first, several companies launched there. Availability changes quickly, so compare current options in our best plug-in solar kits guide and check each product’s certification. The first UL 3700 certifications only arrived in 2026, and many kits sold earlier relied on UL 1741-listed microinverters.
Safety basics that the law assumes
- Use a GFCI-protected outdoor outlet.
- Do not use an extension cord or power strip.
- Keep the solar circuit free of heavy loads like space heaters.
- Secure panels against Utah’s canyon winds; see wind-proofing a balcony installation.
Utah’s influence on other states
Utah’s short, permissive law set the pattern: a wattage cap, certification, anti-islanding and an exemption from interconnection. Later states added pieces Utah left out. Virginia and Colorado added renter protections; Maine created a lighter tier for very small devices; New Jersey named UL 3700 explicitly; Maryland and Virginia added a notification step. Utah remains one of only two states, with New Jersey, where the utility plays no role at all. How the state laws compare.
A worked example for Salt Lake City
A renter in Salt Lake City installs a 600 W kit vertically on a south-facing balcony with light shade. Expected output: 0.6 kW × 1,600 kWh/kW × 0.72 × 0.85 ≈ 590 kWh a year. With a daytime baseload of around 250 W, about 85% of that is used at home: roughly 500 kWh. At 13 cents per kWh, the saving is about $65 a year, so a $500 kit pays back in under eight years. Moving the same kit to a tilted stand in a small yard would raise output to around 960 kWh a year.
Frequently asked questions
Do I need to tell Rocky Mountain Power?
No. HB 340 does not require notification, approval or fees for a qualifying device.
Can I install two kits?
The law defines a device by its maximum output of 1,200 W. Two devices adding up to more than that would fall outside the simple framework. Stay within 1,200 W in total unless you go through standard interconnection.
Can my HOA stop me?
HB 340 does not override HOA rules. Check your covenants and ask the board in writing.
Does the law cover batteries?
It focuses on solar generation devices. A battery system that feeds power through an outlet should meet the same limits and certification; check the product’s documentation.
Summary for general information, not legal advice. See the enrolled text of H.B. 340 (2025 General Session) on the Utah Legislature website.